Marking device for torque applying tool

ABSTRACT

A marking device operable in conjunction with a tool of the type for applying a predetermined torque to a rotatable fastening member to mark the fastening member for indicating that the predetermined torque has been achieved. The tool torques the fastening member through a rotatable work spindle which, in turn, is driven by a socket member carried by a fluid motor. The marking device, which is adapted to be carried by the tool or to be mounted remotely therefrom, comprises a housing having a piston adapted to forcibly eject a marking agent either through a tube extending through the interior of the spindle to mark the fastening member, or through a tube mounted externally of the tool to mark the article carrying the fastener. The marking device is operable to mark the fastening member or the article in response to a pressure fluid signal generated by the torque applying tool upon the predetermined torque being applied to the fastening member.

United States Patent [191 Peterson Nov. 11, 1975 1 MARKING DEVICE FORTORQUE APPLYING TOOL I [75] Inventor: Rudolph G. Peterson, Detroit,Mich.

[73] Assignee: Carco, Inc., Detroit, Mich.

[22] Filed: Sept. 24, 1973 [2]] Appl. No.: 400,382

Related US. Application Data [62] Division of Ser. No. 147.456. May 27.1971, Pat. No.

Primary E.\'aminerStanley H. Tollberg Assistant E.\'aminerHadd LaneAttorney, Agent, or FirmGifford, Chandler & Sheridan ABSTRACT A markingdevice operable in conjunction with a tool of the type for applying apredetermined torque to a rotatable fastening member to mark thefastening member for indicating that the predetermined torque has beenachieved. The tool] torques the fastening member through a rotatablework spindle which, in turn, is driven by a socket member carried by afluid motor. The marking device. which is adapted to be carried by thetool or to be mounted remotely therefrom, comprises a housing having apiston adapted to forcibly eject a marking agent either through a tubeextending through the interior of the spindle to mark the fasteningrne'mber. or through a tube mounted externally of the tool to mark thearticle carrying the fastener. The marking device is operable to markthe fastening member or the article in response to a pressure fluidsignal generated by the torque applying tool upon the predeterminedtorque being applied to the fastening member.

6 Claims, 19 Drawing Figures US. Patent Nov.11,1975 Sheet10f4 3,918,609

US. Patent Nov. 11,1975 Sheet30f4 3,918,609

US. Patent Nov. 11, 1975 Sheet 4 of 4 MARKING DEVICE FOR TORQUE APPLYINGTOOL RELATIONSHIP TO OTHER APPLICATIONS The present application is adivisional of Application Ser. No. 147,456 filed May 27,1971 and now US.Pat. No. 3,802.30l.

BACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention relates to a tool for applying a predetermined torque to arotatable fastening member and particularly to means for marking themember to indicate the completed application of the predeterminedtorque. l

II. Description of the Prior Art It is a recognized fact that to achievea maximum efficiency for fasteners, such as a bolt and nut assembly or athreaded fastener engaged in a threaded bore the nut must be tighteneddown on the bolt or the fastener must be engaged in the bore to such anextent that a predetermined minimum tension is exerted on the bolt orfastener shank. This minimum tension may be'exceeded, but it must be atleast reached for best results. One method, which has been commonlyemployed to insure the attainment of the predetermined tension orpreload ofthe bolt shank, is a method which involves determining thetorque which is required to achieve the desired tension, then oncehaving determined the torque for a particular size bolt, each nut istightened to this predetermined torque.

Pneumatically operated tools, such as nut runners, are ideally suitedfor such applications as the nut runner can repetitively and accuratelyapply a predetermined torque to the nut. In using nut runners or thelike for applying a predetermined torque to bolts, nuts and the like inmechanical assemblies, it is desirable to apply a mark to each boltand/or nut which has been tightened so that an assembler and/or aninspector can thus ascertain whether any of the bolts -or nuts have beenmissed and thus save time by eliminating the retightening of bolts ornuts which are already sufficiently tight. Typical prior art torquewrenches or nut runners are adapted to apply a mark, such as ink orpaint, simultaneously with the engagement with the bolt or nut. By thistechnique, however, the bolt or nut may be improperly marked, that is,the bolt or nut will be marked even if the tightening operation isinterruptedprior to completion of full torque. Thus, the desired resultof marking the nut or bolt to indicate whether a certain torque has beenapplied is not achieved.

SUMMARY OF THE INVENTION The present invention, which will besubsequently described in greater detail, comprises a marking deviceoperable in conjunction with a torque applying tool of the type whichdelivers a predetermined torque to a rotatable fastening member, such asa bolt or nut, wherein the tool generates a signal, such as a fluidpressure, pneumatic, mechanical or electrical signal, which isindicative of a predetermined torque having been delivered to thefastening member, while the marking device in response to the signalmarks the member with a suitable marking agent only upon the completedapplication of the predetermined torque.

It is therefore an object of the present invention to provide a markingdevice adapted to mark a rotatable 2 fastening member only after apredetermined torque has been delivered to the fastening member.

Other objects, advantages, and applications of the present inventionwill become apparent to those skilled in the art of such marking deviceswhen the accompanying description of several examples of the best modes.contemplated for practicing the invention is read in conjunction withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The description herein makes referenceto the accompanying drawings wherein like reference numerals refer tolike parts throughout the several views, and in which:

FIG. 1 is a side elevational view of a right angle nut runner toolincluding a marking device of the present invention;

FIG. 2 is a top plane elevational view of the nut runner tool shown inFIG. 1;

FIG. 3 is a fragmentary cross-sectional view taken along line 33 of FIG.2;

FIG. 4 is a fragmentary cross-sectional view taken along line 4-4 ofFIG. 3;

FIG. 5 is a fragmentary cross-sectional view taken along line 55 of FIG.1 illustrating the marking device of FIG. 1 in a non-operative position;

FIG. 6 is a cross-sectional view similar to FIG. 5 but illustrating themarking device in an operative position;

FIG. 7 is a fragmentary cross-sectional view taken along line 77 of FIG.5 illustrating the marking device in a non-operative position;

FIG. 8 is a cross-sectional view similar to the marking deviceillustrated in FIG. 7 but shown in an operative position;

FIG. 9 is a fragmentary cross-sectional view of the marking device asseen generally along line 9-9 of FIG. 5;

FIG. 10 is a fragmentary side elevational view of a right angle nutrunner with a marking device of the present invention mounted externallyof the housing of the nut runner and adjacent the front portion thereof;

FIG. 11 is a fragmentary side elevational view of an in-line nut runnerwith the ejecting end of a marking device mounted externally of thehousing of the nut runner and adjacent the front portion thereof;

FIG. 12 is a side elevational view of the marking device illustrated inFIG. 1 and shown as being remotely mounted from the nut runner;

FIG. 13 is a fragmentary, partially sectioned side elevational view of amodified marking device mounted rearwardly of the handle portion of anut runner;

FIG. 14 is a fragmentary, partially sectioned top elevational view ofthe modified marking device shown in FIG. 13;

FIG. 15 is a cross-sectional view of the modified marking device takenalong line 1515 of FIG. 13;

FIG. 16 is a cross-sectional view of the modified marking device takenalong line 1616 of FIG. 15;

FIG. 17 is a fragmentary, partially sectioned view of the modifiedmarking device shown in FIG. 14 and il- Ius trated in a differentoperative position;

FIG. 18 is a cross-sectional view of the modified marking device takenalong line 18-18 of FIG. 16; and FIG. 19 is a cross-sectional view ofthe modified marking device taken along line 19-19 of FIG. 13.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the drawings, atorque applying tool. such as a pneumatic, right angle nut runner 10, isillustrated in FIGS. 1 and 2 as comprising an elongated cylindricalhousing 11 including a motor portion 12, a handle portion 13 of areduced diameter, and a front portion 14 carrying a rotatable spindle 15(FIG. 1) of the type adapted to be connected to a conventional wrenchsocket 16 for driving nuts, bolts and the like. A motor 17, which may beof any conventional type of fluid motor such as a rotary vane air motor,is mounted in the motor portion 12 for driving the spindle 15 by meansof a shaft 18 and a bevel gear arrangement 19. The shaft 18 and thespindle 15 are both supported by suitable bearings, such as indicated bythe numerals 20 and 21. A marking device 22, which will be described ingreater detail hereinafter, is mounted on top of the motor portion 12 ofthe nut runner 10, however, as will be likewise described hereinafter inan alternate embodiment, the marking device 22 may be mounted rearwardlyof the handle portion 13 or mounted remotely from the nut runner 10.

Compressed air for driving the fluid motor 17 is supplied through an airhose 23 coupled at the rear of the handle portion 13 to the nut runner10 and flows through a suitable inlet screen 24 disposed in a passageway25 (see FIG. 3) which, in turn, comprises a series of passages that leadto the fluid motor 17. Still referring to FIG. 3, an inlet passage 26 ofthe passageway 25 communicates with a double diameter valve chamber 27defined by a bushing 28 fixed in one end of a bore 29 and extendingacross the housing 11, and by an air regulator 30 closing the other endof the bore 29. The air regulator 30 includes an inner cup-like member31 forming an enlarged end of the valve chamber 27 and a shank portion33 of a reduced diameter which, in turn, is received in a hollow plug 32screwed into the bore 29. The inner cup-like member 31 is restrainedagainst unintended movement by means of an O-ring 34 encircling theshank portion 33 and recessed on the inner end of the plug 32.

An inlet port 36, formed in the wall of the cup-like member 31, servesto connect the inlet passage 26 and the chamber 27, while the volume ofair admitted into the chamber 27 is governed by rotatably adjusting theposition of the member 31 so that it can vary the effective size of theinlet port 36, the adjustment being facilitated by a screwdriver slot 38which is easily accessible at the outer end of the shank portion 33.Assuming a load of established value, the operator may thus vary thepower of the motor 17 and the spindle speed to suit the application ofthe nut runner 10.

A throttle valve 40 is received in chamber 27 and has a stem 41projecting out through the bushing 28, while an inner stem of thethrottle valve 40 is enlarged relative to the stem 41 and is furtherprovided with an annular flange 44 on one side of which is mounted anannular seal 46, which, in turn, is engageable with the inner end of thebushing 28. The other side of the flange 44 is seated on a compressionspring 48 and is biased between the flange 44 and member 31 so as tohold the throttle 40 in a normally closed position. The throttle valve40 is provided with a graduated intermediate portion 49 which is taperedfrom an enlarged portion 42 of the throttle valve 40 to its end 41 forthe purpose of effectively minimizing the initial pressure surge of airsupplied to the motor 17.

To actuate the motor 17, a hand lever 50, pivotally supported on thehousing 11 rearwardly of the marking device 22 and engaging the outerprojecting end of the stem 41, is compressed to unseat the throttlevalve 40, whereupon air enters chamber 27 through the inlet port 36 topass through an outlet port 52 and the bushing 28, communicating with aninlet passage 54 to a normally opened shut-off control valve 56 andtherethrough to an outlet passage 58 (FIG. 4) to the motor Stillreferring to FIG. 4, a bore 60 extending across the housing 11transversely of the bore 29 receives a sleeve 61 having an end extension62 and an outlet passage 64 disposed radially outwardly of a circularcompartment 63, so as to connect a chamber 65 with an outlet 66, whichis suitably threaded to receive a fluid coupling such as at 67. Thesleeve 61 has an open inner end adapted to abut a coaxially alignedhollow plug 68 screwed into the opposite end of the bore 60. The sleeve61 is rigidly fixed in position by any suitable means, such as by apressfit.

For automatically shutting off air flow to the motor 17, a valve plungeror spool 69 is received in the chamber 65, defined by the inner surfaceof the sleeve 61, for reciprocating movement between open and closedpositions, respectively at the left and right ends of the chamber 65 asviewed in FIG. 4. The end extension 62 of the sleeve 61 and the innerend of the plug 68 provide seats for the spool 69 respectively in itsopen and closed positions. The spool 69 is illustrated as being normallyheld open in its left hand position by a coil spring 70, having one endbearing against the bottom of a cup-shaped cavity 71 in the spool 69,while the opposite end of the spring is seated within a threaded bore 72extending through the plug 68.

So that the spool 69 is responsive to variations in the motor operatingpressure, which are a function of the output force of the motor 17 andin this way is responsive to a predetermined level of torque beingreached, passages in communication with the outlet passage 58 areprovided for continually directing compressed air against the spool 69to provide a force in opposition to the spring force when the spool 69is in its opened position as shown in FIG. 4. More specifically, apassage 73 is shown as extending diametrically through a reducedintermediate portion 74 of the spool 69 and another passage 75 extendsfrom passage 73 axially through the left hand end of the spool as viewedin FIG. 4 to provide'internal passage means of a generally T-shapedcross section. Passages 73 and 75 are in eommunication with an outletport 76 in the sleeve 69, which connects to the outlet passage 58leading to the motor 17 when the spool 69 is in its opened position.

Still referring to FIG. 4, the compartment 63, formed in the extensionend 62, is of a circular cross section and is adapted to receive anannular extension 77 of a reduced diameter formed at the left end of thespool 69 and surrounding the axial passageway 75. The compartment 63 andthe annular extension 77 are dimensioned to provide a preselectedclearance between the spool 69 and the extension end 62 of the sleeve61. This clearance preferably is maintained by an O-ring 78 retained ina groove 79 around the extension 77 to provide a fluid-tight seal aroundthe compartment 63 when the spool 69 is in its open position as shown inFIG. 4. Thus, the end of the spool extension 77 provides a pressuresensing surface 80 which is in communication with the outlet passage 58when the spool 69 is in its open position, the area of the pressuresensing surface 80 being relatively small with respect to the area ofthe annular end surface 81 of the spool 69 surrounding the extension 77.

To provide a torque control which is highly sensitive to variations inthe output force or torque of the motor 17 as indicated by a change inthe static pressure in the outlet passage 58, a drop in the air supplypressure at the inlet of the motor 17 is intentionally created acrossthe spool 69. For this purpose, a restricted port or orifice 82 isformed in the sleeve 61. It will be apparent that for a given size airmotor and a given minimum supply air pressure, the torque at whichshut-off automatically takes place is determined by the force of thespring 70. To produce the shut-off at a desired maximum torque value, anadjustment member 83 is provided for precisely varying the spring forceexerted on the spool 69. Member 83 is provided with an aperture 84 whichserves to vent air trapped behind the spool 69 when the same is snappedclosed, that is, when the spool 69 is moved to close communicationbetween the passages 54 and 58.

Upon movement of the spool 69 to a shut-off position, air from thesupply pressure line enters into the chamber 65 to the left of the spool69 by means ofinlet passage 54, a slot 92 and an orifice 94. By virtueof this construction, inlet air will be directed to the outlet 66 upon amovement of the spool 69 into its shut-off position, thereby sensing thecondition of the tool and automatically providing a fluid signal to theoutlet 66, which signal is indicative of the completed tool operation,that is, that a predetermined amount of torque has been delivered to thenut or bolt through the spindle 15.

Upon reaching the preset shut-off torque, the pressure acting upon thesmall pressure sensing surface 80 of the extension 77 within thecompartment 63 reaches a predetermined value which is sufficient toovercome the atmospheric pressure and the force of spring 70 and thespool 69 shifts slightly to the right of the compartment 63 to unseatthe O-ring 78, and then suddenly snaps to a closed position when thelarge end surface 81 of the spool 69 is exposed to back pressure of themotor 17. At this time, air flow is shut-off to the motor inlet and airis directed from the chamber 65 through a coupling tube 98 to actuatethe marking device 22 housed on top of the motor portion 12 in a mannerwhich will be described hereinafter. As will also be describedhereinafter, the coupling tube 98 may be connected to a marking device22 mounted rearwardly of the handle portion 13 or mounted remotely fromthe nut runner 10.

Upon releasing the lever 50, the valve 40 returns to a normally closedposition, permitting the spool 69 to return to its normally openposition under the force of spring 70 and in readiness for the nextoperating cycle.

It should be noted that the nut runner has been described in detail butonly for purpose of illustration and other mechanisms which generate asignal of any kind after a predetermined torque has been applied to arotatable fastening member may be used in conjunction with the presentinvention to mark the rotatable fastening member.

Referring now to FIGS. 5-9, there is illustrated the preferred markingdevice 22 particularly adapted for use in conjunction with the nutrunner 10. The marking device 22 comprises cylindrical housing portions102, 104, and 105 and a rectangularly shaped end cover 112 secured toone another by screws 113 (FIGS. 7 and 8) extending through the cover112, housing portions 104, and into threaded bores 106 within thehousing portion 102.'The housing portion 104 has a cup-shaped bore 114opening to the inner face 115 of the housing portion 105 and supports apiston for sliding recip rocal movement toward and away from the housingportion 102. The housing portion 102 has a longitudinally disposed boreaxially aligned with the cupshaped bore 114 and slidably receiving apiston extension 128 extending from one surface of the piston 120.

The longitudinal bore 130 of the housing portion 102 communicates with adecreased diameter bore 132 (FIGS. 7 and 8) which forms an inlet 134 ofafeed passage 136, the outlet of which terminates at an ink coupling tube138 (FIG. 5) which is mounted to the top of the front portion 14 of thenut runner 10. The coupling tube 138 extends through an axial bore 139(FIG 1) of the hollow spindle 15 and terminates in a nozzle 141 throughwhich the marking agent is ejected. Referring again to 7 and 8,downstream of the inlet 134 the feed passage 136 forms a valve seat onwhich a floating spherically shaped valve member 144 is normally seated.The valve member 144 is in an enlarged chamber 145 axially aligned withthe bore 132 and opens into the ink coupling tube 138 through arestricted pas sageway 137 that forms the outlet of the feed passage136. The restricted passageway 137 is formed in a threaded member 147which serves to connect the ink coupling tube 138 to the marking device22 and which provides a guide for a coil spring 150 having one endbearing against the member 147 and its other end acting against thevalve member 144 to normally seat the same on valve seat 140 to closecommunication between the bore 132 and the restricted passageway 137.The valve member 144 is movable between an upstream positin where it isseated on the valve seat 140 under the force of the spring 1150 to closecommunication between the feed passage inlet 134 andthat portion of thefeed passage 136 downstream of the valve seat 140 and an. open positionin which the valve member 144 is unseated to permit a marking agent tobe ejected externally of the marking device by means of the restrictedpassageway 137 to the ink coupling tube 138, whereby the ejected markingagent is directed through the hollow portion of the spindle 15 to markthe top of the engaged fastening member (FIG. 1). The valve member 144is unseated when pressure acts on the same in a manner which will bedescribed in greater detail hereinafter.

Still referring to FIGS. 78, a portion of the longitudinal bore 130 ofthe marking device 22 adjacent the inlet 134 of the-feed passage 136forms a reservoir 152 for containing a quantity of the fluid markingagent. The fluid marking agent within the reservoir 152 is replenishedby an external reservoir (not shown) through inlet 156 and a hose 157(FIGS. 1 and 2).

The piston extension 128 has an enlarged section 158 which slidablyengages the bore 130 and is reciprocated by the piston 120 in responseto the selective pressurization ofchambers 159 and 161 formed on theopposite sides of the piston 120. The projecting end of the pistonextension 128 forms a pumping element 160 which is movable between aretracted position as illustrated in FIGS. 5 and 7, wherein it is spacedfrom the inlet 134 and the feed passage 136 and fluid within thereservoir 152 is freely communicable to the feed passage 136, and anextended position illustrated in FIGS. 6 and 8 in which the pumpingelement 160 enters the feed passage inlet 134 to close communicationbetweem the feed passage I36 and the reservoir 152 separating a slug ofthe fluid marking agent within the feed passage 136 from the reservoir152. The pumping element 160 is of a cylindrical shape complementary tothe shape of the bore 132 and so sized that when the element 160 engagesthe bore 132 there is a fluid seal between the outer periphery of thepumping element 160 and the inner surface of the bore 132 so that thefluid trapped within the feed passage 136 will not leak back into thereservoir 152.

As the pumping element 160 is stroked to its extended position as willbe described hereinafter, it will raise the pressure of the trappedfluid within the feed passage 136 so as to generate a force ofsufficient magnitude to move the valve member 144 off the seat 140against the bias of the spring 150. The charge of marking fluid is thendelivered under pressure past the valve member 144, through thepassageway 137 externally of the marking device 122, through the inkcoupling tube 138, the hollow spindle and to the engaged fasteningmember to mark the same. As the pumping element 160 starts to return toits retracted position, the spring 150 acts against the valve member 144to cause the same to again engage the seat 140. As the valve member 144seats, a vacuum is created in the feed passage 136 and as retraction ofthe pumping element 160 continues, communication between the feedpassage inlet 134 and the reservoir 152 is open and the amount of fluidejected from the marking device 22 is replenished therein. The seatedvalve member 144 prevents the passage of the fluid marking agent fromthe feed passage 136 until the pumping element 160 is again shifted toits extended position.

Reciprocal movement of the piston 120 is produced by selectivelypressurizing the chambers 159 and 161 on the opposite side of the piston120 by means of a shuttle valve 162, best seen in FIGS. 5 and 6. Thevalve 162 comprises a spool 164 slidably mounted in a bore 166 formedwithin the cover 112. The spool 164 has a plurality of longitudinallyspaced lands 168, 170 and 172 separated by annular spaces 174 and 176defined by the interior of the bore 166 and the outer surface of thespool 164. The annular space 176 between lands 170 and 172 communicateswith one end of the bore 166 through a T-shaped internal passageway 178,said one end of the bore 166 being vented to atmosphere through anaperture 180 extending through a plug member 182 that threadedly engagesthe cover 112 in axial alignment with the bore 166.

A source of fluid pressure, which in the present embodiment is the airsupply utilized to actuate the nut runner 10, is communicated to a port184 (FIGS. 7, 8 and 9) at the top of the cover 112 by means of an airsupply tube 186 and is so disposed that pressurized air is normally fedto the annular space 174 between the lands 168 and 170. Movement of thespool 164 along the axis of the bore 166 permits communication betweenthe annular space 174 in one position (FIG. 6) and a port 188 connectedto the chamber 161 through drilled passageways 189 in the housingportion 105, and in a second position with a port 192 that is connectedto the chamber 159 through drilled passageways 194 and 196 in thehousing portions 105 and 104, respectively. A spring 198 carried by theplug member 182 normally biases the spool 164 to the positionillustrated in FIGS. 5 and 9 wherein the annular space 174 normallycommunicates with the inlet port 192 and passages 194 and 196 so as todirect air under pressure to the chamber 159 to generate a force on thepiston to move the piston rightwardly and maintain the same in theposition shown in FIGS. 5 and 7. As best seen in FIGS. 5 and 6, the endof the bore 166 opposite the spring 198 is threaded to receive a fitting200 which is connected to the tube 98 leading from the end extension 62of the shut-off control valve 56 within the nut runner 10.

It can thus be seen that when pressure from the shutoff valve 56 isexhausted through the end extension 62 to the end of the bore 166,pressure will act against the spool face 202 to shift the spool 164downwardly against the bias of the spring 198 to the positionillustrated in FIG. 6, whereby pressurized air is communicated from theannular space 174 through the port 188 and passages 189 to the chamber161, generating a force against the piston 120 to move the sameleftwardly to the extended position shown in FIGS. 6 and 8 to achievethe aforementioned pumping action by the pumping element 160. As thepiston moves leftwardly to an extended position, the air within thechamber 159 is exhaustd through the passages 194, 196, the port 192, theT-shaped passage 178 and vent aperture 180. As long as the lever 50 isheld down and pressurized air is directed from the extension end 62 ofthe shut-off valve 56 to the cover 112 the spool 164 will be held in theposition shown in FIGS. 6 and 8 and pressure will be directed againstthe piston 120 to maintain the same in its extended position; however,only one slug of the fluid marking agent will be ejected to mark thefastening member.

As soon as the lever 50 is released, the pressure on the spool face 202of the valve spool 164 will be relieved, whereupon the spring 198 willshift the spool 164 upwardly to the position shown in FIG. 5, at thesame time closing off the communication between the annular space 174and the port 188, while opening up communication between the annularspace 174 and the port 192, thereby directing pressurized air to thechamber 159 while the chamber 161 is exhausted through the passage 189,the port 188 and the vent aperture 180 as the land 178 traverses theport 188. The pressurized air communicated to the chamber 159 generatesa force against the piston 120 to move the piston 120 back to itsretracted position shown in FIGS. 5 and 7, wherein fluid communicationbetween the feed passage inlet 134 and the reservoir 152 is again openedand the unit is in position to eject another slug of the fluid markingagent to mark the next fastening member when a predetermined torque hasbeen applied thereto.

In operation, the nut runner 10 is actuated by depressing the lever 50whereby pressurized air is communicated to the motor 17, which in turndrives the rotating spindle 15 to apply a predetermined amount of torqueto the nut, bolt or the like that is engaged by the socket 16. After thepredetermined amount of torque has been applied to the fastening member,a pressure signal in the form of pressurized air is emitted from theshut-off valve 56 and is communicated to the end of the spool 164 in thecover 112. The pressurized air acts against the spool 164 to move thesame into the position illustrated in FIG. 6, thereby fluidly connectingthe high pressure air from air supply tube 186 to the chamber 161,generating a force against the piston 120 to shift the pistonleftwardly, and thus the pumping element to its extended position. Whenthe pumping element 160 is so driven, the same enters the feed passagebore 132 to close communication between the feed passage inlet I34 andthe reservoir 152, thereby trapping a charge ofthe fluid marking agenttherein. As the pumping element 160 traverses the bore 132 toward theend of its stroke (which is determined by the engagement of an enlargedportion 204 of the piston 120 with the blind end of the cup-shaped bore114 of the housing portion 104), the pressure of the fluid within thebore 132 is raised to a sufficient level to move the valve member 144offthe seat 140 against the bias of the spring 150, whereby fluid isdischarged from the marking device 22 through the ink coupling tube 138to mark the engaged fastening member. The discharge end of the 'ink tube138 is reduced in cross-section to form a'small orifice which retains asolid ink bank in the tube and gives good direction to the ink jetaction to mark the device. A vacuum created upstream in the tube 138retains the ink within the tube.

When the lever 50 is released and the air pressure being directedagainst the spool face 202 is relieved, the spring 198 will return thespool 164 to the position illustrated in FIG. 5, thereby directingpressure fluid to the chamber 159 while venting the chamber 161, therebygenerating a force against the piston 120 to move the same rightwardly.With the pumping element 160 in its fully retracted position asillustrated in FIG. 5, fluid communication between the reservoir 152 andthe inlet 134 of the feed passage 136 is again opened and the markingdevice is ready to commence another stroke to eject the fluid markingagent to mark the engaged fastening member after the predeterminedtorque is delivered.

Referring to FIG. 10 of the drawings, a modification of the markingdevice 22 is illustrated with the coupling tube 138 mounted to the outersurface of the front portion 14 of the nut runner 10 adjacent thespindle 15, rather than extending into the spindle as illustrated inFIG. 1, such that the marking agent ejected from the marking device 22will mark the article or workpiece to which the fastening member isbeing attached rather than the fastening member itself when apredetermined torque is delivered to the fastening member. Asillustrated in FIG. 10, the coupling tube 138 is fastened to one side ofthe front portion 14 of the nut runner 10 by any suitable means, as forexample a tape 206.

In FIG. 11 the coupling tube 138 of the marking device 22 is shown asbeing mounted to the front portion 214 of a pneumatic, in-line notrunner 216 by means of the tape 206' and enables the marking device tofunction in an identical manner as heretofore described, in that amarking agent is ejected through the coupling tube 138 to mark aworkpiece or other article to which the fastening member has beensecured with the marking device 22 being actuated by a fluid signalgenerated by the nut runner 10 (or 216) and as indicated hereinbefore,such a signalmay be in the form of a fluid pressure, an electrical or amechanical signal.

FIG. 12 illustrates the marking device 22 as being remotely mounted fromthe nut runner l0 and adapted to mark a workpiece or article 218 when apredetermined torgue has been delivered to a fastening member 219 thatis secured to the workpiece 218. The marking de vice 22 is illustratedas being mounted on a support base 220 and is so positioned that acharge of marking fluid will be delivered under pressure through thepassageway 137 or any other small orifice member and externally thereofto mark a portion of the workpiece 218 which is spaced a relativelyshort distance from the marking device 22. The marking device 22illustrated in FIG. 12 is identical to the marking device 22 describedheretofore with the supply tube 186 being coupled to a source ofpressure. the hose 157 communicating with an external ink reservoir (notshown). and the coupling tube 98 being adapted to direct air from thechamber to actuate the marking device 22 in the manner describedhereinbefore.

Referring now to FIGS. 13-19, and in particular FIGS. 13, 14 and 19, amodification of the marking device 22 is illustrated in the form ofamarking device assembly 250 adapted to be coupled to'the air inlet ofthe nut runner 10. The marking device assembly 250 comprises an air hosecoupling member 252 having a longitudinally disposed bore 254 forcommunicating pressurized air between the hose 23 and the air inlet ofthe nut runner 10. The opposite ends of the coupling memher 252 arerespectively connected to the air inlet of the nut runner 10 and the airhose 23 by conventional air fittings 253 and 255.

As can best be seen in FIGS. 13 and 19, the coupling member 252 isprovided with an upper annular recess 256 on which a marking device 300is seated and secured by screws 258 extending radially upwardly throughthe wall of the coupling member 252 and threadingly engaging bores 260in the underside of the marking device 300. Access to the screws may behad through diametrically opposed bores 262 in the lower portion of thecoupling member 252 which. in turn, are closed by plug members 264 asshown in FIG. 13.

Referring to FIGS. 15, 16, and 17, the marking device 300 is illustratedas comprising six axially aligned cylindrically shaped housing portions,including a pumping portion 302, a bypass vent plate 303, a piston driveportion 304, a porting plate 305, a valve body portion 306 and an endcover 308, all of which are secured to one another by screws 312extending through the cover 308, valve body portion 306, porting plate305, piston drive portion 304, bypass vent plate 303 and into threadedbores (unnumbered) within the pumping portion 302. The drive portion 304has a cupshaped bore 314 opening to the inner face 315 of the portingplate 305 and supports a piston 320 for sliding reciprocable movementtoward and away from the pumping portion 302. The pumping portion 302,the bypass vent plate 303 and the adjacent face of the piston driveportion 304 have an axially aligned bore 330 which is axially alignedwith the cup-shaped bore 314 and slidably receives a piston extension328 extending from one surface of the piston 320. The faces of thepumping portion 302 and the piston drive portion 304 adjacent the bypassvent plate 303 are each provided with an annular recess 33] torespectively accommodate a Teflon O-ring 333 and an elastomer O-ring 325for a purpose to be described hereinafter. The diametrical clearancebetween the piston extension 328 and that portion of the bore 330associated with the bypass vent plate 303 is very small so as to providea wiping action of the piston extension 328 as the same is reciprocated.

As viewed in FIGS. 15 and 16, that portion of the longitudinal bore 330within the pumping portion 302 forms a feed passage 336, the outlet ofwhich terminates at the ink coupling tube 138. The opposite end of thecoupling tube 138 may be mounted in any of the configurations describedhereinbefore with respect to the embodiments disclosed in FIGS. 1, 10,11 and 12. Downstream from the piston extension 328, the feed passage336 forms a valve seat 340 on which a truncated shape valve member 344is normally seated (FIG. 17 The valve member 344 is loosely slidablymounted in a fitting 345, the inner end of which forms an enlargedchamber 347 (FIG. which communicates with the feed passage 336 when thevalve member 344 is unseated in a manner which will be describedhereinafter. The diametrical clearance between the valve member 344 andthe fitting 345 is sufficiently large to communicate the enlargedchamber 347 with the interior of the fitting 345 which, in turn,communicates with the coupling tube 138 through a restricted passage 351in a manner similar to that described in the embodiments of FIGS. 1-9.The fitting 345, in addition to connecting the ink coupling tube 138 tothe marking device 300, provides a guide for a coil spring 350 havingone end bearing against the fitting 345, while its other end actsagainst the valve member 344 to normally seat the same on the valve seat340 (FIG. 17) to close communication between the feed passage 336 andthe restricted passageway 351.

The valve member 344 is movable between an upstream position wherein itis seated on the valve seat 340 under the force of the spring 350toclose communication between the feed passage 336 and that portion ofthe feed passage 336 downstream of the valve seat 340 and an openposition in which the valve member 344 is unseated to permit a fluidmarking agent to be ejected externally of the marking device 300 aroundthe valve member 344, through the restricted passageway 351 and into theink coupling tube 138, whereby the ejected marking agent is directed tomark the top of the engaged fastening member or the article to which thefastening member is secured in the same manner as described in theembodiments illustrated in FIGS. l-12. The valve member 344 is unseatedwhen pressure acts on the same in a manner which will be described ingreater detail hereinafter.

Still referring to FIGS. l319, and particularly to FIGS. 15, 16 and 17,a portion of the longitudinal bore 330 of the marking device 300communicates with radially disposed passageways 352, each of wichterminates at a threaded bore 353. One of the bores 353 is adapted toreceive a fitting 354 to connect the feed passage 336 to an externalreservoir (not shown) by means of an ink supply hose 357 (FIG. 14),while the opposite threaded bore 353 is closed by plug member 355 (FIG.14). Thus the user is provided with convenient means for coupling theink supply hose 357 to the opposite side of the marking device 300 so asto more easily aeeommodate various mounting configurations andapplications which may be encountered in using the marking device 300.

The piston extension 328 is reciprocated by the piston 320 in responseto the selective pressurization of chambers 359 and 361 formed in theopposite side of the piston 320 within the drive portions 304. Theprojecting end of the piston extension 328 forms the pumping portion ofthe marking device and is movable between a retracted positionillustrated in FIG. 17, wherein the end of the piston extension 328 isspaced from the radially extending passages 352 such that fluid from theexternal reservoir is freely communicated to the feed passage 336, andan extended position illustrated in FIGS. 15 and 16 in which theprojecting end of the piston extension 328 enters the feed passage 336to close communication between the feed passage 336 and the radiallyextending passages 352, thus separat- 12 ing a slug of the fluid markingagent within the feed passage 336 from the external reservoir.

The end of the piston extension 328 is of a cylindrical shapecomplementary to the shape of the feed passage 326 and is so sized thatwhen the piston extension 328 is slidably reciprocated within the feedpassage 336 there is a fluid seal between the outer periphery of thepiston extension 328 and the surface of the feed passage 336 so thatfluid trapped within the feed passage 336 will not leak back into theexternal reservoir.

As the end of the piston extension 328 is stroked to its extendedposition, as will be described hereinafter, it will raise the pressureof the trapped fluid within the feed passage 336 so as to generate aforce of sufficient magnitude to move the valve member 344 off the seat340 against the bias of the spring 350. The charge of marking fluidwithin the feed passage 336 is then delivered under pressure past thevalve member 344, through the passageway 351 and externally of themarking device 300, and through the ink coupling tube 138 to mark theengaged fastening member as described hereinbefore with respect to theembodiments disclosed in FIGS. l-12.

As the piston extension 328 returns to its retracted position, thespring 350 acts against the valve member 344 to cause the same to againengage the valve seat 340. As the valve member 344 seats, a vacuum iscreated in the feed passage chamber 336 and as retraction of the pistonextension 328 continues, communication between the feed passage 336 andthe external reservoir is opened and the amount of fluid ejected fromthe marking device 300 is replenished within the feed passage. Theseated valve member 144 prevents the passage of the fluid marking agentfrom the feed passage 336 until the piston extension 328 is againshifted to its extended position.

Still referring to FIGS. 15-17, it can be seen that reciprocal movementof the piston 320 is produced by selectively pressurizing the chambers359 and 361 on the opposite sides of the piston 320. This isaccomplished by means of a shuttle valve 362 housed within the valvebody portion 306. The valve 362 comprises a spool 364 slidably mountedin a bore 366, the bore extending completely through the valve bodyportion 306 and opening to the adjacent inner face of the porting plate305 and end cover 308. The spool 364 has a plurality of longitudinallyspaced lands 368, 370 and 372 separated by annular spaces 374 and 376defined by the interior of the bore 366 and the outer surface of thespool 364.

The annular space 374 between the lands 370 and 372 communicates withthe inner end of the bore 366 through a T-shaped internal passageway 378within the spool. The inner end of the bore 366 is, in turn, vented toatmosphere through an aperture 380 extending through the end cover 308.

A source of fluid pressure, which in the present embodiment is the airsupply from the hose 23, is communicated to a passage 384 (FIGS. 16 and18) through a port 385. The passage 384 extends through the wall of thecoupling member 252 and is so disposed that pressurized air from theport 385 is normally communicated to the annular space 374 between thelands 368 and 370.

Movement of the spool 364 along the longitudinal axis of the bore 366 tothe position shown in FIGS. 15 and 16 permits communication between theannular space 374 with a port 388 (FIG. 15) which is connected to thechamber 361 through longitudinally drill passageways 390 and 391respectively in the valve body portion 306 and the porting plate 305.Movement of the spool 364 to a second position as shown in FIG. 17permits communication of the annular space 374 with a port 392 (FIG. 16)that is connected to the chamber 159 through drill passageways 394, 395and 396 respectively in the valve body portion 306, porting plate 305and the plate drive portion 304. A spring 398 disposed between the spool364 and a recess 399 formed on the inner face ofthe end cover 308normally biases the spool 364 to the position illustrated in FIG. 17wherein the annular space 374 normally connects the ports 392 and 385 soas to direct air under pressure to the chamber 359 to generate a forceon the piston 320 to move the piston rightwardly and maintain the piston320 in the position shown in FIG. 17.

As can best be seen in FIGS. 14 and 15, the valve body portion 306 has athreaded connection port 401 for receiving a fitting 400 which is inturn connected to the coupling tube 98 leading from the end extension 62to shut-off control valve 56 within a nut runnner as hereinbeforedescribed. The inner end of the bore 366, that is the end between theporting plate 305 and the inner end 402 of the spool 364, is in fluidcommunication with the fitting 400 through a passageway 403 disposed inthe valve body portion 306 and the porting plate 305.

It can thus be seen that when pressure from the valve 56 in the nu'trunner 10 is exhausted through the end extension 62 to the inner end ofthe bore 368 through passageway 403, pressure will act against the spoolface 402 to shift the spool 364 rightwardly, as viewed in FIGS. 15 and16, against the bias of the spring 398 to the position illustrated inFIGS. 15 and 16, whereby air pressure is communicated'through theannular space 374 from the port 388 to the chamber 361 to generate aforce against the piston 320 to move the same leftwardly and to theextended position shown in FIGS. 15 and 16 to achieve the aforementionedpumping action of the piston extension 328. As the piston 320 movesleftwardly to the extended position, the air within the chamber 359 isexhausted through the passageways 394, 395 and 396, the port 392, theT-shaped passage 378 and the vent aperture 380.

As long as the lever 50 of the nut runner 10 is held down andpressurized air is directed from the extension 62 and the inner shut-offvalve 56 to the end 402 of the spool 364, the same will be held in theposition shown in FIGS. 15 and 16 and pressure will be directed againstthe piston 320 to maintain the same in the extended position. However,only one slug of the fluid marking agent will be ejected to mark thefastening member or the article to which the fastening member issecured, depending upon the specific application and embodinent used asdescribed hereinbefore in FIGS. 1-12.

As soon as the lever 50 of the nut runner 10 is reveased, the pressureon the inner end 402 of the spool 364 will be relieved, whereupon thespring 398 will shift the spool 364 leftwardly to the position shown inFIG. 17, at the same time closing off communication )etween the annularspace 374 and the port 388, while )pening up communication between theannular recess ;pace 374 and the port 392, thereby directing pressur zedair from the air hose 23 to the chamber 359, while :he chamber 361 isexhausted through the port 388 and vhe aperture 380. Pressurized aircommunicated to the :hamber 359 generates a force againt the piston 320to nove the piston 320 back to its retracted position as shown in FIG.17 wherein fluid communication between the feed passage 336 and! theexternal reservoir is again open and the unit is in position to ejectanother slug of the fluid marking agent to mark the next fasteningmember when a predetermined torque has been applied thereto as describedhereinbefore. The O-rings 333 and 325 prevent the passage of air fromthe chamber 359 to the ink supply and vice versa, while a ventingpassage 410 in the vent plate permits any such leakage to vent to theatmosphere.

In operation, the nut runner 10 is actuated by depressing the lever 50,whereby pressurized air is communicated to the motor 17 which, in turn,drives the spindle 15 to apply a predetermined amount of torque to thenut, bolt or other fastening member that is en gaged by the socket 16.After a predetermined amount of torque has been applied to the fasteningmember, a signal in the form of pressurized air is emitted from theshut-off valve 56 and communicated to the inner end 402 of spool 364.The pre'ssuried air acts against the spool 364 to move the same to theposition illustrated in FIGS. 15 and 16, thereby fluidly connecting thehigh pressure air from the air supply hose 23 to the chamber 361,generating a force against the piston 320 to shift the pistonleftwar'dly and thus the piston extension 328 to its extended position.When the piston extension 328 is so driven, it enters the feed passage336 to close off communication between the passage 336 and the radiallyextending passage ways 352 communicating with the external reservoir,thereby trapping a charge of the fluid marking agent within the feedpassage 336.

As the extension member 328 traverses the feed passage 336 toward theend of its. stroke (which is determined by the engagement of an enlargedportion 404 of the piston 320 with the blind end of the cup-shaped bore314) the pressure of the fluid within the feed passage 336 is raised toa sufficient level to move the valve member 344 off the seat 340 againstthe bias of the spring 350. Fluid is thereby discharged from the markingdevice 300 through the ink coupling tube 138 and to'the interior of thespindle 15 to mark the engaged fastening member or is discharged to theexternal mounting assembly illustrated in FIGS. 10 and 11 to mark thearticle or workpiece to which the fastening member is'to be secured.

When the lever 50 is released and the air pressure being directedagainst the inner end 402 of spool 364 is relieved, the spring 398 willreturn the spool 364 to the position illustrated in FIG. 17, therebyventing the chamber 361 while directing pressure fluid to the chamber359, generating a force against the piston 320 to move the samerightwardly. With the piston extension 328 in its fully retractedposition as illustrated in FIG. 17, fluid communication between theexternal reservoir and the feed passageway 336 is again open and themarking device is ready to commence another stroke to eject the fluidmarking agent to mark the engaged fastening member or the workpiececarrying the fastening member when a predetermined torque has beendelivered to the fastening member.

It can thus be seen that the present invention has provided a markingdevice for a torque applying tool, such as a nut runner, forautomatically placing a marking agent on a rotatable fastening member ora workpiece engaged by the fastening member to indicate the completedapplication of a preselected torque to the fastening member, and whichfastening member cannot be so marked until a predetermined torque hasbeen reached.

The invention can take many forms and can be used in combination withany type of nut runner which will generate some type of signal when thepredetermined torque has been achieved. While in the disclosedembodiments a pneumatically driven nut runner has been described andthus the signal indicating completion of the predetermined torque is inthe form of a fluid signal, it is apparent that with appropriatemodifications the present invention could be used with a nut runnerwhich generates a mechanical or electrical signal when the predeterminedtorque has been achieved.

What is claimed is as follows:

1. A markingdevice adapted to eject a marking fluid unto a workpieceupon completion of a predetermined operation being performed upon saidworkpiece, said operation requiring a fluid pressure system and anincrease in the pressure within said system to a predetermined valuebeing achieved upon completion of said operation, said marking devicecomprising:

a reservoir of said marking fluid;

a feed passage having an inlet in communication with said reservoir andan outlet through which said marking fluid is ejected;

rmeans for closing communication between said reservoir and said feedpassage for separating the fluid in said feed passage from the fluid insaid reservoir; and

means responsive to the pressure in said fluid pressure system achievinga predetermined value indicating the completion of the operation on saidworkpiece to pressurize said separated fluid in said feed passage toforcibly eject said separated fluid through said feed passage outlet.

2. The marking device defined in claim 1 wherein said means for closingcommunication between said reservoir and said feed means comprises apiston member movably mounted within said reservoir between a firstposition in which said piston engages the inlet of said feed passage toclose communication between said reservoir and said feed passage, and asecond position in which said piston means is spaced from said inlet topermit fluid communication between said reservoir and said feed passage.

3. The marking device defined in claim 2 and in which said fluidpressure system comprises a source of 16 fluid pressure and saidpressure responsive means comprises valve means for selectivelycommunicating said source of pressure to said piston member from saidfirst position in said second position.

4. The marking device defined in claim 3 wherein said valve meanscomprises a spool valve slidably disposed in a bore in said markingdevice housing, said bore having spaced ports, one of which is incommunication with said chamber on one side of said piston and the otherport being in communication with said chamber on the other side of saidpiston, said source of fluid pressure being communicated to said bore,said spool valve having means for connecting said source of fluidpressure to one port for moving said piston to said second positionwhile exhausting the chamber on the other side of said piston; and meansnormally biasing said spool valve to a position wherein said chamber onthe other side of said piston is normally exhausted.

5. The marking device defined in claim 1 wherein said means forpressurizing said fluid in said feed passage comprises:

a chamber;

a piston movably mounted in said chamber, said piston being movablebetween a first position in which said piston engages the inlet of saidfeed passage to close communication between said reservoir and said feedpassage to forcibly eject said separated fluid from the feed passage tomark said rotatable fastening member and a second position in which saidpiston is spaced from said inlet to permit fluid communication betweensaid reservoir and said feed passage;

a source of fluid pressure; and

a valve means responsive to the pressure in said fluid pressure systemachieving said predetermined value to communicate said source of fluidpressure to one side of said piston to move said piston to said firstposition.

6. The marking device defined in claim 5 wherein said valve means isadapted to communicate said source of fluid pressure to the other sideof said piston to move said piston to said second position upon thepressure in said fluid pressure system falling below said predeterminedvalue.

I UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION q PATENT NO.3,918,609

DATED 3 November 11, 1975 INVENTOR(S) Rudolph G. Peterson It iscertified that error appears in the above-identified patent and thatsaid Letters Patent Qt are hereby corrected as shown below:

Col. 6, line 36, delete "positirt' and insert --position- Col. 9, line48, delete "not" and insert -nut Col. 9, line, 61, delete "torque" andinsert -torque- Col. ll, line 42, delete "wich" and insert which-- Col.14, line 20, deletef'pressuried" and insert --pressurized- Col l6 line 4delete "in" and insert -to- Signed and Sealed this Q seventeenth Day OfFebruary 1976 [SEAL] Attesl:

RUTH C. MASON C. MARSHALL DANN Arresting Officer (ummissioner of Patentsand Trademarks

1. A marking device adapted to eject a marking fluid unto a workpieceupon completion of a predetermined operation being performed upon saidworkpiece, said operation requiring a fluid pressure system and anincrease in the pressure within said system to a predetermined valuebeing achieved upon completion of said operation, said marking devicecomprising: a reservoir of said marking fluid; a feed passage having aninlet in communication with said reservoir and an outlet through whichsaid marking fluid is ejected; means for closing communication betweensaid reservoir and said feed passage for separating the fluid in saidfeed passage from the fluid in said reservoir; and means responsive tothe pressure in said fluid pressure system achieving a predeterminedvalue indicating the completion of the operation on said workpiece topressurize said separated fluid in said feed passage to forcibly ejectsaid separated fluid through said feed passage outlet.
 2. The markingdevice defined in claim 1 wherein said means for closing communicationbetween said reservoir and said feed means comprises a piston membermovably mounted within said reservoir between a first position in whichsaid piston engages the inlet of said feed passage to closecommunication between said reservoir and said feed passage, and a secondposition in which said piston means is spaced from said inlet to permitfluid communication between said reservoir and said feed passage.
 3. Themarking device defined in claim 2 and in which said fluid pressuresystem comprises a source of fluid pressure and said pressure responsivemeans comprises valve means for selectively communicating said source ofpressure to said piston member from said first position in said secondposition.
 4. The marking device defined in claim 3 wherein said valvemeans comprises a spool valve slidably disposed in a bore in saidmarking device housing, said bore having spaced ports, one of which isin communication with said chamber on one side of said piston and theother port being in communication with said chamber on the other side ofsaid piston, said source of fluid pressure being communicated to saidbore, said spool valve having means for connecting said source of fluidpressure to one port for moving said piston to said second positionwhile exhausting the chamber on the other side of said piston; and meansnormally biasing said spool valve to a position wherein said chamber onthe other side of said piston is normally exhausted.
 5. The markingdevice defined in claim 1 wherein said means for pressurizing said fluidin said feed passage comprises: a chamber; a piston movably mounted insaid chamber, said piston being movable between a first position inwhich said piston engages the inlet of said feed passage to closecommunication between said reservoir and said feed passage to forciblyeject said separated fluid from the feed passage to mark said rotatablefastening member and a second position in which said piston is spacedfrom said inlet to permit fluid communication between said reservoir andsaid feed passage; a source of fluid pressure; and a valve meansresponsive to the pressure in said fluid pressure system achieving saidpredetermined value to communicate said source of fluid pressure to oneside of said piston to move said piston to said first position.
 6. Themarking device defined in claim 5 wherein said valve means is adapted tocommunicate said source of fluid pressure to the other side of saidpiston to move said piston to said second position upon the pressure insaid fluid pressure system falling below said predetermined value.